Molecular characterization and transcriptional analysis of the female-enriched chondroitin proteoglycan 2 of Toxocara canis

LvCPG2 facilitated WSSV infection by interaction with VP26 and VP28

Chondroitin sulfate proteoglycans (CSP), widely distributed in extracellular matrices, have several important functions in vertebrates. In certain viruses, CSP acts as a receptor to promote infection. However, chondroitin proteoglycans lack sulfate are poorly understood in invertebrates. In this study, chondroitin proteoglycan 2 of Litopenaeus vannamei (LvCPG2) was cloned. The open reading frame of LvCPG2 cDNA is 2133 bp, which encodes a protein of 710 amino acids. LvCPG2 contained eight Chitin-binding domain type 2 (ChtBD2). LvCPG2 had the highest expression in lymphoid and significantly increased after WSSV challenge. The relative expression of IE1 and VP28, as well as the viral copy numbers were decreased significantly in LvCPG2-silenced shrimp. The far-western blotting result showed that LvCPG2 interacted with VP26 and VP28. Molecular docking complexes showed that N-terminal of LvCPG2 interacted with C-terminal VP26, while C-terminal of LvCPG2 combined with N-terminal of VP28. Flow cytometry analysis indicated that LvCPG2 could facilitate WSSV adhesion and penetration of shrimp hemocytes. Collectively, these findings suggested that LvCPG2 was involved in WSSV infection by interaction with VP26 and VP28.

Tissue expression pattern of ABCG transporter indicates functional roles in reproduction of Toxocara canis

Toxocara canis is a zoonotic parasite with worldwide distribution. ATP-binding cassette (ABC) transporters are integral membrane proteins which involve in a range of biological processes in various organisms. In present study, the full-length coding sequence of abcg-5 gene of T. canis (Tc-abcg-5) was cloned and characterized. A 633 aa polypeptide containing two conserved Walker A and Walker B motifs was predicted from a continuous 1902 nt open reading frame. Quantitative real-time PCR was employed to determine the transcriptional levels of Tc-abcg-5 gene in adult male and female worms, which indicated high mRNA level of Tc-abcg-5 in the reproductive tract of adult female T. canis. Tc-abcg-5 was expressed to produce rabbit polyclonal antiserum against recombinant TcABCG5. Indirect-fluorescence immunohistochemical assays were carried out to detect the tissue distribution of TcABCG5, which showed predominant distribution of TcABCG5 in the uterus (especially in the germ cells) of adult female T. canis. Tissue transcription and expression pattern of Tc-abcg-5 indicated that Tc-abcg-5 might play essential roles in the reproduction of this parasitic nematode.